FLORHAM PARK, N.J. — Rex Ryan welcomed his players back to work after the bye-week break, and immediately sensed something different around the New York Jets’ facility.

There was overwhelming enthusiasm throughout the halls and meeting rooms. And that had been missing in previous years when the team returned to work.

“I don’t know if I really felt that coming back in, that energy or as Brian Billick would say, that synergy,” Ryan said Monday afternoon. “Just that kind of, `Wow. We’re excited to be back here.”’

At 5-4, Ryan’s Jets have been one of the NFL’s biggest first-half surprises, shaking off outside projections for a dismal season. They’re still holding a playoff spot in the AFC, but know they have plenty of work to do to stay there.

For one, they have alternated wins and losses all season, tying an NFL record through nine games, and are looking for their first winning streak. But Ryan insisted his team is looking only at trying to beat the Bills (3-7) at Buffalo on Sunday.

“Nobody’s thinking about, `Hey, let’s run seven in a row off,”’ Ryan said. “Yeah, I’ll sign up for it. The only way to get there is to handle your business, and that’s what we have to do.”

Ryan even visited his brother Rob, the Saints’ defensive coordinator, in New Orleans to catch up and “get some intel on Buffalo” since the Saints beat the Bills two weeks ago.

New York faces just one opponent with a winning record the rest of the way — Carolina (6-3) in Week 15 — although Miami (4-4) was playing Tampa Bay on Monday night. Buffalo, Baltimore (4-5), Oakland (3-6) and Cleveland (4-5) are all sub-.500.

“To place ourselves for the playoffs, (we have to) take it one game at a time, but that’s our goal, make the playoffs and go from there,” tight end Kellen Winslow Jr. said. “I don’t see why we can’t win them all, though.”

That’s the confidence that a promising start has bred for the Jets, a team some said would be lucky to win four games all season.

“Winning definitely helps,” rookie quarterback Geno Smith said. “I think we have a great opportunity in front of us and that’s where the excitement lies because we know that as a team, our best football is ahead of us.”

But in order to reach that point, the Jets have a handful of things to take care of in order to keep those playoff hopes well into late-December:

— Good Geno. Just as the team has gone, Smith has been up and down from game to game with eight touchdown passes and 13 interceptions. That inconsistency needs to change, but the Jets are doing all they can to not put too much pressure on the rookie.

“Understand that you’re one of 11 and you don’t need to do it all by yourself,” Ryan said of Smith. “With that being said, he’s got tools where he can make a difference in a positive way.”

— Getting Healthy. The Jets’ wide receivers and tight ends have been the walking wounded this season, with Santonio Holmes, Stephen Hill, Jeremy Kerley, Jeff Cumberland and Clyde Gates all missing time with injuries.

Holmes, who has missed five games with a hamstring injury, could return this week.

The Jets are getting Winslow back, which should be a big help, after he served a four-game suspension for violating the NFL’s policy on performance-enhancing substances.

— Running The Ball. Despite offensive coordinator Marty Mornhinweg’s love for throwing the ball, he has shown he is willing to adapt and that has made this year’s Jets similar to the team’s 2009-10 “Ground-and-Pound” offense.

Chris Ivory has put hamstring issues behind him and been the hard-running presence the Jets expected when they traded for him in April. He has run for 254 yards in his past three games, teaming with Bilal Powell to form the NFL’s ninth-best running attack. That will be huge as the weather turns cooler — and will help Smith from trying to do too much with his arm.

— Better Pass Defense. Once the strength of the team, the Jets’ secondary has been suspect while ranking 23rd in the league against the pass.

Antonio Cromartie, who replaced Darrelle Revis as New York’s No. 1 cornerback, has been shaky at times. Top draft pick Dee Milliner has also had a rough start to his career, dealing with injuries and ineffectiveness. But, the good news is this: The Jets don’t face a top passing offense the rest of the season. The best is Baltimore, which is 14th.

“We have been inconsistent and we’ve shown flashes of being a good team, but we’ve also had moments where we haven’t looked so good,” Smith said. “We know that as long as we clean up our mistakes and we handle the things that we can control, we’ll have an opportunity.”